User:Bioprof-Mohamed Salem/sandbox

Biology Mitosis cell divisionItalic text Mitosis NotesItalic text Cell division occurs in a series of stages, or phases. • Chromatids (or pairs of chromosomes) separate and begin to move to opposite ends of the cell • Chromatids (or pairs of chromosomes) attach to the spindle fibers • Chromosomes are copied (# doubles) • Chromosomes appear as threadlike coils (chromatin) at the start,but each chromosome and its copy (sister chromosome) change to sister chromatids at end of this phase • Mitosis begins (cell begins to divide) • Centrioles (or poles) appear and begin to move to opposite ends of cell. • Spindle fibers form between the poles • Two new nuclei form • Chromosomes appear as chromatin (threads rather than rods) • Mitosis ends • Cell membrane moves inward to create two daughter cells - each with its own nucleus with identical chromosomes 1st: INTERPHASE 2nd: PROPHASE 3rd: METAPHASE Sister chromatids 4th: ANAPHASE Sister chromatids split 5th: TELOPHASE 6th: CYTOKINESIS Sister chromatids Centromere Mitosis: The process by which cells reproduce themselves, resulting in daughter cells that contain the same amount of genetic material as the parent cell. Stages of Mitosis: 1-ProphaseItalic text: ●Replicated chromosomes condense and become visible. ●46 chromosomes composed of two sister chromatids. ●Nuclear membrane breaks down. ●Spindle fibers form. 2-MetaphaseItalic text : ●Chromosomes, with spindle fibers attached, move to middle of cell. 3-AnaphaseItalic text:

●Centromeres divide. ●Converts each sister chromatid to a chromosome. ●Chromosomes migrate to opposite ends of cell. ●Complete set of 46 chromosomes at each end of cell. 4-'TelophaseItalic text'' ●Final stage of mitosis ●Chromosomes unwind ●Spindle fibers break down ●Nuclear membrane re-forms Cytokinesis: Last Stage of Cell Cycle ●Cell membrane constricts and divides cell into two daughter cells with 46 chromosomes.